Chorioretinitis in Cats: A Vet’s 2025 Guide to Posterior Eye Inflammation 🐱👀
By Dr Duncan Houston, BVSc
🔍 What Is Chorioretinitis?
Chorioretinitis—also known as posterior uveitis—is an inflammation of the choroid (vascular retina layer) and retina. It often arises from systemic illness and can threaten vision through retinal swelling, hemorrhage, or detachment.
⚠️ Why It Happens: Common Causes
- Infectious agents: Toxoplasma gondii (ocular toxo), FIP, FeLV, FIV, fungal (Histoplasma, Cryptococcus) or bacterial sepsis.
- Hypertension: High blood pressure leading to vascular damage and retinal hemorrhage.
- Immune-mediated or systemic disease: Vasculitis, neoplasia, or idiopathic posterior uveitis.
- Trauma or toxins: Eye injury, severe infections, or toxins like antifreeze.
🚩 Signs & Symptoms
- Minimal or no pain unless anterior uveitis is present
- Cloudy or inflamed vitreous, “floaters,” bleeding or liquefaction
- Fundoscopic lesions: fluffy grey-white patches, hemorrhages, retinal detachment
- Vision loss, dilated pupils, anisocoria, or altered reflexes
- Occasional ocular pain, redness, tearing, squinting if anterior segment is involved
🔬 Diagnostic Steps
- History & physical: Assess systemic illness, eye changes, breed, age.
- Complete eye exam: Ophthalmoscopy with pupil dilation to visualize posterior inflammation.
- Fundus photography: Documents lesions, hemorrhage, and retinal detachment progression.
- Blood & urine labs: Rule out FeLV, FIV, toxoplasmosis, systemic hypertension, organ dysfunction.
- Imaging: Thoracic/abdominal imaging for infection, neoplasia; ocular ultrasound for detachment or masses.
- Ocular fluid sampling: Aqueous or vitreous tap + PCR/cytology in select infectious cases.
🛠️ Treatment Approaches
A. Treat Underlying Cause
- Antiparasitics: Clindamycin for toxoplasmosis 2–4 weeks.
- Antivirals/antifungals: Fluconazole or itraconazole for crypto/histoplasmosis.
- Antibiotics: Broad-spectrum (doxycycline, azithromycin) for bacterial causes.
- Antihypertensives: Amlodipine to control systemic hypertension.
- Immunosuppressives: Prednisone or azathioprine for immune-mediated disease.
B. Control Inflammation
- Systemic steroids: Prednisone until underlying infection ruled out or treated.
- Topical anti-inflammatories: Atropine to relieve pain & prednisolone acetate for anterior uveitis involvement.
- Glaucoma meds: If secondary elevated intraocular pressure is present due to uveal inflammation.
C. Supportive & Monitoring Care
- Regular eye exam and intraocular pressure checks throughout therapy.
- Continue systemic treatment until resolution of lesions and systemic disease.
- Protect eyes from trauma, UV light, and ensure comfortable environment.
📅 Aftercare & Prognosis
- Vision prognosis depends on severity and retinal involvement—retinal detachment carries guarded outlook.
- Persistent lesions may leave scarring; routine monitoring is essential.
- Lifelong antihypertensive drugs may be necessary for hypertensive cats.
- Recheck blood pressure, general health, ocular exams every 3–6 months.
- Secondary complications (cataracts, glaucoma) require timely ophthalmic treatment.
📝 Quick Reference Table
| Aspect | Details |
|---|---|
| Definition | Inflammation of retina & choroid (posterior uveitis) |
| Causes | Infection, hypertension, immune-mediated, trauma/toxins |
| Signs | Vitreous haze, hemorrhage, lesions, vision loss |
| Diagnosis | Ophthalmoscopy, labs, imaging, ocular fluid tests |
| Treatment | Anti-infective/immunosuppressives + anti-inflammatories |
| Prognosis | Good if early—vision loss possible in severe cases |
🐾 Chorioretinitis signals deeper health issues requiring prompt and thorough veterinary care. With early diagnosis and tailored treatment—targeting underlying causes, controlling inflammation, and preventing complications—many cats retain vision and quality of life. For ongoing eye care support, use the Ask A Vet app. Provide a calm, safe space and vision-friendly lighting with comforts from Woopf & Purrz. Your cat’s sight matters—stay vigilant and proactive! ❤️
📢 Always follow your veterinarian’s guidance for diagnosis, treatment decisions, and follow-up care.
© 2025 AskAVet.com
This article is general veterinary education and does not diagnose or treat an individual animal. Always confirm medication names, doses and interactions with the veterinarian who knows your pet.
If your animal is struggling to breathe, collapsed, bleeding heavily, seizing, or has eaten something toxic, contact your vet or the nearest emergency clinic now.
Animal Poisons Helpline (AU) 1300 869 738 · Animal Poisons Helpline (NZ) 0800 869 738 · ASPCA Animal Poison Control (US) (888) 426-4435
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Ask A Vet articles are written by Dr Duncan Houston BVSc, a practising veterinarian, unless another author is named in the byline.




